title: TEL-AML1 fusion transcript in relapsed childhood acute lymphoblastic leukemia. The Berlin-Frankfurt-Münster Study Group.
abstract: The cryptic translocation t(12;21)(p13;q22) has been recently recognized as the most common genetic rearrangement in B-lineage childhood acute lymphoblastic leukemia (ALL). The resulting fusion transcript, termed TEL-AML1, has been associated with an excellent prognosis at initial ALL diagnosis. Hence, we postulated that the incidence of TEL-AML1 fusion should be lower in patients with ALL relapse. To address this assumption and to investigate the prognostic significance of TEL-AML1 expression in relapsed childhood ALL, bone marrow samples of 146 children were analyzed by reverse-transcriptase (RT)-polymerase chain reaction (PCR). All children were treated according to Berlin-Frankfurt-Münster (BFM) ALL relapse trial protocols (ALL-REZ BFM 90-96). Their clinical features and outcome were compared with those of 262 patients who could not be tested due to lack of bone marrow samples. Thirty-two of 146 children with relapsed ALL were TEL-AML1-positive. Four of the negative patients had T-lineage and nine Philadelphia chromosome (Ph)-positive leukemia. Thus, the incidence of TEL-AML1 in relapsed Ph1-negative, B-cell precursor ALL is 32 of 133 (24%). The 32 TEL-AML1-positive and 101 negative patients differed significantly with respect to duration of last remission (42.5 v 27 months; P = . 0001) and age at initial diagnosis (53.5 v 74 months; P = .0269). At a median follow-up time of 21.5 months, children positive for TEL-AML1 had a significantly (P = .0011) higher probability of event-free survival (EFS; 0.79 v 0.33). The predominant majority of patients had been treated for initial ALL according to German multicenter BFM (108 of 133) or Cooperative ALL study group (CoALL) (19 of 133) frontline protocols. The comparison of tested and not-tested (N = 262) patients showed no significant difference. TEL-AML1 positivity predicted a favorable short-term outcome; long-term results are unknown. Screening for TEL-AML1 should become routine at relapse diagnosis and might be used for therapy stratification in future trials.
authors.affiliation: Department of Pediatric Oncology/Hematology, Charit-e-Virchow-Klinikum, Humboldt-University at Berlin, Berlin, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Seeger
authors.forename: H P
authors.initials: HP
authors.lastname: Adams
authors.forename: D
authors.initials: D
authors.lastname: Buchwald
authors.forename: B
authors.initials: B
authors.lastname: Beyermann
authors.forename: B
authors.initials: B
authors.lastname: Kremens
authors.forename: C
authors.initials: C
authors.lastname: Niemeyer
authors.forename: J
authors.initials: J
authors.lastname: Ritter
authors.forename: D
authors.initials: D
authors.lastname: Schwabe
authors.forename: D
authors.initials: D
authors.lastname: Harms
authors.forename: M
authors.initials: M
authors.lastname: Schrappe
authors.forename: G
authors.initials: G
authors.lastname: Henze
mesh_terms: D000293:Adolescent; D001853:Bone Marrow / Q000737:chemistry; D002648:Child; D002675:Child, Preschool; D002881:Chromosomes, Human, Pair 12; D002891:Chromosomes, Human, Pair 21; D050676:Core Binding Factor Alpha 2 Subunit; D018572:Disease-Free Survival; D006801:Humans; D009363:Neoplasm Proteins / Q000235:genetics*; D015514:Oncogene Proteins, Fusion; D016133:Polymerase Chain Reaction; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics* / Q000401:mortality / Q000628:therapy; D011379:Prognosis; D012333:RNA, Messenger / Q000032:analysis*; D012194:RNA-Directed DNA Polymerase; D012008:Recurrence; D012074:Remission Induction; D014178:Translocation, Genetic; D000097764:ETS Translocation Variant 6 Protein
chemical_list: D050676:Core Binding Factor Alpha 2 Subunit; D009363:Neoplasm Proteins; D015514:Oncogene Proteins, Fusion; D012333:RNA, Messenger; D012194:RNA-Directed DNA Polymerase; C102421:TEL-AML1 fusion protein; D000097764:ETS Translocation Variant 6 Protein